Centrifugal pumps are generally constructed of an impeller housed in a casing. The impeller includes a number of vanes for imparting centrifugal force to liquid during impeller rotation, moving the liquid radially outward to the discharge side of the pump. Displacement of the liquid by the impeller vanes creates negative pressure at the impeller eye assisting in suction of additional liquid into the pump. A suction liner can be positioned between the inlet side of the casing and the impeller.
Slurry centrifugal pumps present several challenges related to the abrasive characteristics of the slurry. Highly abrasive conditions encountered in the mining of oil sands, for example, place extreme wear stress on pump components, especially the impeller and suction liner. Impeller vanes and suction liner surfaces can quickly erode inducing premature retirement of these components. Such retirement is often out of cycle with the maintenance of other apparatus, leading to increases in downtime of the mining operation. In view of these problems, impeller design is under continuous development to enhance wear characteristics. Impellers, for example, have become larger to permit lower velocities at the vane leading edge, thereby reducing impact forces of slurry particles. Larger impeller size also enables longer vanes for increased operating lifetime. Additionally, suction liners have received design updates to combat wear. Segmented wear plates have been applied to suction liner surfaces. Moreover, weld overlay claddings have been imparted to suction liners. While generally increasing suction liner lifetime, these surface modifications present tribological disadvantages. Seams and joints associated with segmented plates and weld overlay can be sites of enhanced wear and untimely failure.